As a frame rate conversion method, there is a method of adding a frame between adjacent frames (see Patent document 1). Further, for interpolation of a video frame, there is a 2-3 pulldown scheme for converting a 24-frame video of a video film into an interlaced signal exhibiting 60 fields per second. Then, in order to smooth the motion of an image, there is a method of determining a movement amount from a pixel difference and applying the movement amount to the interpolation according to the 2-3 pulldown scheme (see Patent document 2).    [Patent document 1] Japanese Laid-open Patent Publication No. 2005-124201    [Patent document 2] Japanese Laid-open Patent Publication No. 2006-165602